Case Study
Data collection of rural water supply network by QGIS/QField for O&M work of water systems in Rwanda
By Rural Water and Sanitation Services Department(RWSS), Water and Sanitation Corporation (WASAC), Rwanda
To conduct data collection of all rural water supply network in Rwanda, and keep updating the data continuously in order to improve operation & maintenance of waterworks.
Before starting our data collection, we conducted the following things.
- Develop our own PostGIS database (see our ER diagram here)
- Develop QGIS project template with Geopackage. The Geopackage table design should be equal to PostGIS. So we can just copy and paste to PostGIS.
Of course, it requires Android devices in order to use QField. However, we recommend to use new version of Android as much as possible, because we found QField didn't work well in some old version's Android. Also, if possible, you can purchase GPS devices. In WASAC, we bought Garmin GPSMAP 64S. Sometimes, GPS of smartphone and tablet is not very accurate, so we normally capture the same location by using Garmin GPS, then correct the location of QField's data after data collection work.
Once we prepared Geopackage and QGIS project template, we conducted training of QGIS/QField in July 2018 and launched our data collection work in 27 districts in the whole country of Rwanda. 27 engineers sent their Geopackage to central office in Kigali, the MIS specialist validated and entered their data from Geopackage to PostGIS database. We completed our initial data collection works until April 2019.
The most significant thing after data collection is updating. We have seen many organization in Africa, they normally failed to keep updating. Several years later, their data will normally become too old, and most of them need to put efforts on data collection again. However, WASAC is continuously updating all of the data until now. We think QField works very well for this purpose.
In order to distribute and updating the data, we developed a python script postgis2qfield. This postgis2qfield tool can extract the data from PostGIS and create Geopackages for each districts in Rwanda. We upload these 27 geopackage together with QGIS project template to Google Drive storage. After that, those engineers in districts download their geopakage to Android device to continue adding and updating the data. Once they completed updating, send geopackage to central office again, MIS specialist update PostGIS database and regenerate geopackages for QField.
Why didn't we use QFieldSync plugin for this purpose? Although QField has a nice QFieldSync plugin for linking between PostGIS and Geopackage, we didn't select QFieldSync. Because QFieldSync plugin only can create a Geopackage only, so size of data will become so large, it makes QField's performance slow. After separating PostGIS data into 27 geopackages by postgis2qfield, the performance of QField is better now.
Since July 2020, we started to distribute our water supply systems' data via vectortiles as open data. Although Rwanda's internet situation is being improved, some rural area still have problems of internet. In such as poor internet situation, WMS or WFS data distribution will not work well. Vectortiles can provide light and fast distribution of map data. We will not talk about our vectortiles here. Please have a look our following website on Github. If you are fascinated by how to share the result of data collection, please also see this instruction.
- Water Supply Map for WASAC RWSS: Our WebGIS website. You can see the data which was collected by QField.
- vt: This is actual repository where we stored vectortiles on GitHub Pages.
We thank all of district water and sanitation support engineers to conduct their data collection work. Additionally, we want to thank the developers of QField and QGIS for offering fantastic open source software. It is great that, due to free software, such projects can be implemented by an organization of water sector in developing countries.
WASAC has 2 main departments for urban water(UWSS) and rural water(RWSS). We are using QField in RWSS. The role of RWSS department is to support local government to operate and maintain their owned water supply systems in rural area. Nowadays, these data collected and maintained by RWSS department are being used by more than 30 private operators in 27 districts. Total number of water supply systems in the database is 1,100+.
Also, one of our colleagues presented WASAC's activity in FOSS4G 2019 Bucharest. Although some of system were little bit changed now, you can also see video if you are interested.